Pumice Stone
Pumice called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.
Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases (including water and CO2) that are dissolved in the lava, causing the gases to rapidly exsolve (like the bubbles of CO2 that appear when a carbonated drink is opened). The simultaneous cooling and depressurization freeze the bubbles in a matrix.
PUMICE STONES USING IN DENIM WASHING
Denim stone washing (or stone wash) is a finishing process used to give an aged and worn-out feature to garments. Additionally, stonewashing also improves the softness of jeans and denim fabrics. The process of stone washing began towards the end of the 1970’s, putting denim garments together with the pumice stones into the washing machines.
As the wash drum rotates, the garments are repeatedly pounded and beaten by the stones, abrading the fibers and the indigo color on the denim fabric. The result is a vintage and worn look on brand new garments.
Which type Pumice stones we are producing?
OHM Pumice produce and ship following calibers:
- 0-4 mm Pumice Stone double washed, three times tumbled
- 3-8 mm Pumice Stone double washed, three times tumbled
- 8-16 mm Pumice Stone double washed, three times tumbled
- 1-2 cm Pumice Stone double washed, three times tumbled
- 1-3 cm Pumice Stone double washed, three times tumbled
- 2-3 cm Pumice Stone double washed, three times tumbled
- 2-4 cm Pumice Stone double washed, three times tumbled
- 3-5 cm pumice stone double washed, three times tumbled
- 5-7 cm pumice stone double washed, three times tumbled
Physical and Chemical Pumice Properties
Pumice is not just pumice—it varies greatly in its physical and chemical properties (and usefulness) from deposit to deposit. Tabled below are the properties for the pumice mined, processed and shipped by OHM.
| Chemical | Value | Unit |
| SiO2 | 70,1-73,32 | % |
| Al2O3 | 12,75-13,72 | % |
| Fe2O3 | 1,08 - 1,39 | % |
| CaO | 0,70-0,73 | % |
| MgO | 0,20 | % |
| 0,08-0,10 | % | |
| K2O | 4,30-4,33 | % |
| Na2O | 3,58-3,75 | % |
| MnO | 0,06 | % |
